The new patch not only added a new character, but changed the model of Drow Ranger.
Abilities of the new hero:
Spear of Mars
Mars throws his legendary Spear, damaging each enemy unit it strikes. The first enemy hero it hits is skewered and pushed back. If a skewered hero hits a tree, building, or cliff, they will be impaled to it and stunned.
Mars smashes enemies in front of him with his shield, knocking them back and damaging them with a critical hit based on his attack. Imbued with True Strike, the assault adds bonus base damage when hitting heroes.
Mars wields his massive shield to block a portion of each physical attack when struck from the front or sides.
Arena of Blood (ultimate)
Mars summons an arena lined with the undead warriors of the Ash Legion, who block enemy attacks and movement. Enemy heroes near the inside edge of the arena will be attacked by spears, dealing damage and knocking them back.
We want to remind that initially Valve were going to release this character in winter, but later they reported that he would be released at the beginning of March. The announce of Mars happened during The International 2018.
According to the statistics, on the first day after the release of the hero, winrate of Mars was 48%. He appeared on off lane, that is in 67% of all matches.
As for the items for Mars, the most useful of them was Assault Cuirass, which was bought more than 15,000 times. At all the matches where Assault Cuirass was bought, the player won 68% of matches. Also other popular items for Mars were Power Treads, Blink Dagger and Vladmir’s Offering.
If we talk about the heroes, the best counter-pick for Mars was Necrophos. At the matches with his participation the new character managed to get a win only in 40% of the matches.
Interesting fact about the rank of the players who picked Mars. Most of all the god of war interested Dota 2 users who have ~2,000 MMR. If we say it more specifically, the new hero appears at every tenth match of these ranks.